The present invention relates generally to the tree harvesting art and, more particularly, to an improved apparatus for felling trees.
For centuries, trees have been commercially harvested on a mass scale for processing of their wood into all forms of timber, lumber, paper and other derivative products. Historically, the initial operation of felling trees at the harvesting site has been carried out manually and, even today, many tree felling operations are performed utilizing only a manually operated hand-held chain saw mechanism. Over recent years, various forms of automated tree felling apparatus have been developed, typically being adapted for mounting to a conventional offroad commercial vehicle such as a so-called front end loader for ready transportation and operation at a harvesting site. Representative examples of such tree felling apparatus and similar tree harvesting equipment are disclosed in U.S. Pat. Nos. 3,565,138; 3,612,115; 3,613,923; 3,672,412; 3,796,242; 3,874,432; 3,881,615; 3,905,104; 3,946,775; 3,991,799; 4,013,106; 4,050,488; 4,053,005; 4,161,200; 4,219,058; 4,219,059 and 4,763,705.
Conventional tree felling apparatus of this type have been relatively slow to gain widespread acceptance within the tree harvesting industry for a variety of reasons. Substantially all known commercially produced felling apparatus are adapted for use only with relatively small diameter trees of no more than 24 inches in diameter and 40 to 50 feet in height, which of course significantly limits the range of harvesting operations with which such apparatus may be effectively used. Further, some felling apparatus utilize relatively large, hydraulically operated, scissor-like cutting blades which, in addition to being limited in use to relatively small trees, normally cause substantial fiber damage to trees felled therewith for several feet of each tree's length above the cutting location, thus making such apparatus entirely unsuitable for harvesting trees to be utilized for the production of furniture and other high grade lumber materials. While other felling apparatus utilize a cutting mechanism of the chain saw type to avoid this problem, the necessary requirement of periodically replacing the cutting chain due to its dulling over use or occasional breakage thereof is disadvantageously a difficult and time consuming operation typically requiring the entire removal or other substantial disassembly of the chain saw mechanism from the felling apparatus for installation of a new cutting chain in endless form or, alternatively, requiring the installation of a non-continuous length of cutting chain and the riveting together of its opposite ends.
In contrast, the present invention provides an improved tree felling apparatus which is suitably stable and effective for felling larger trees of up to 36 inches in diameter and 80 to 100 feet in height and utilizes a uniquely designed arrangement for tensioning the chain of a chain saw mechanism which permits the simple and ready replacement of a worn or broken cutting chain in endless form without any required disassembly of the felling apparatus. Other features and advantages of the present invention will appear from the disclosure hereinafter.